I think your comment manages to be both uncharitable and misleading. Until very recently the MIT campus was extremely open and accessible to everyone. A great many non-mit students have many experiences going places far more dubious, including steam tunnels and machine rooms deep under the buildings. Can you tell me how many of them have been _federally prosecuted_? Can you name even one? If you could then perhaps we can have a good faith discussion about "highly illegal" and "far beyond petty crime".
Even after the new lockdowns ( https://news.ycombinator.com/item?id=33352567 ) the building in question is one of the ones still open to the general public. Tossing your equipment into an equipment closet, to access the exact same network you can access elsewhere but with reduced risk of some vagrant walking off with it is the same thing most people would do if they needed to leave some equipment connected and didn't have access to a more secure location.
There is just no way to deny that what Aaron was being prosecuted for was 'downloading too many scientific papers while having an anti-monopolist mindset'. Any mere urban explorer who arguably trespassed into a school facility would at most be facing a local trespassing charge, and in a case like this where the facility was expressly open to the general public and their unauthorized access was to an unlocked wiring closet, those charges likely wouldn't have stuck (or wouldn't have resulted in a very consequential sentence). Usually trespassers, when caught, are just kicked out and not charged at all. Exactly the sort of "petty crime" not-"highly-illegal" stuff you argue it wasn't.
Is it unfortunate that the feds had an option to cloak their almost nakedly political prosecution behind a complaint of dubious deeds? Wouldn't it have been better (for him) if he'd asked one of his many friends that had offices at MIT if he could leave a computer in their office? Sure. But we don't get to pick the cases that are used to defend our rights, the prosecutors get to pick... and they pick ones they think they have the best odds of winning, or in other words the cases with the best chance of letting them erode our rights, the best chance of having a chilling effect, the best chance of not resulting in a loss for the state that instead strengthens the freedoms they're trying to undermine.
So it's almost inevitable that our privacy is defended through the lens of accused pedophiles our our freedom of speech through obvious racists. The case being unfortunate is a _default_. But by comparison with those, prosecuting Aaron Swartz over this was like federally prosecuting hippy anti-war protesters putting up posters for _littering_. Wouldn't it have been better if did nothing that could be accused of being littering? Yes but the prosecutor would simply have waited for a different case where someone did, and it would just be that case being used to chill the public's freedoms. We could be a lot worse off than fighting for access to (primarily publicly funded!) knowledge through an accused trespasser. The choice of case would matter personally to the accused, but not to us-- if anything it's not hard to imagine a case much more muddled than one against Aaron that they could have used, say someone with a arguable commercial angle or a connection to a hostile state interest. Whatever case is being used as a proxy to attack the rights of all of the rest of us will always have some extra angle making it more complicated.
Sadly Aaron didn't get the support he needed from the public (including myself), he wasn't in the right place to see it through, and the intensity of federal prosecution is just out of odds with producing justice in the face of potentially vulnerable targets. It did end the political aspirations of the prosecutor, for whatever its worth.